Metal Detector

7/17/2019 Metal Detector

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PowerPoint PresentationOn

Simple Metal Detector By

Sourish Bhowmik (Roll No.-25300310060)

Uddipto De ( Roll No.-2530031005!)S"#deep Sh"w (Roll No.-

25300310052)Sir J. C. Bose School of Engineering



•

Introduction• Principle of operation

• Circuit diagram

• Parts list

•Picture of components

• Information about transistor

• BFO detector design

• Advantages and Disadvantages of circuit

• Application

• Conclusion

• Bibliography

• Acknowledgement

TABLE OF CONTENTS



• $et"l dete%tor is " de&i%e th"t %"# dete%tmet"l' the "si%s %"# m"ke " sou#d whe#it is #e"r some met"l.

• %ti&e dete%tor uses the %oil to tr"#smit "pulse or " %o#ti#u"ll w"&e*orm.

• whe# some met"ls "re %omi#+ %lose to the%oil the "mplitude o* the re,e%ti&e pulseis +etti#+ little lower "#d " dur"tio# o*the pulse " little lo#+er.

INTRODUCTION



• he# some met"l is mo&i#+ %lose to" %oil the m"+#eti% eld "rou#d the%oil is %h"#+ed "#d the %oil i#du%tssome e#er+' %"lled /ddie %urre#t.

• * there is me"sured o# the spe"ker"#d pushes " little to thememr"#e' the spe"ker +e#er"tes

some e#er+.

• he #eed *or dete%tio# is &er %le"r

to prote%t our sel* *rom "# ki#d o*



•

# our %ir%uit os%ill"tor will produ%e " shi*t i#*reue#%. he e#d result is " dete%tor th"toper"tes like two-tr"#sistor %ir%uit.

• $et"l p"ssi#+ throu+h the set o* %oils %re"tes"# im"l"#%e whi%h the i#ter#"l %ir%uitrse#ses "s " si+#"l o* #ite "mplitude "#dde#ite ph"se "#+le with respe%t to "

re*ere#%e si+#"l supplied the os%ill"tor.

• # our met"l dete%tor %ir%uit two &"ri"le%"p"%itors "#d loop "re used to +e#er"teos%ill"tio# i# the %ir%uit.

PRINCIPLE OF OPERATION



• #%re"si#+ the &"lue o* the &"ri"le%"p"%itor will lower the os%ill"tors

*reue#% "#d de%re"se the &"lue withi#%re"se the *reue#%.

•

4ere i# our met"l dete%tor %ir%uittr"#sistor is used "s " %olpittsos%ill"tor.

• * we i#%re"se 1s i#du%t"#%e it will%"use the de%re"se i# *reue#% "#d i*we de%re"se this 1s i#du%t"#%e it

will %"use the i#%re"se i# *reue#%.



CIRCUIT DIAGRAM



• 1."p"%itors- %17 .01u*' %27 .0001u*'%37 .005u*' %57 8-38p*' %67 12-

100p*' %87 .1u* • 2. r"#sistor- 91(2N3:08)

• 3. Resist"#%es- R17 1;' R27 2!0;

•

8. <ower sour%e- :=• 5. Swit%h- S1

• 6.oop- 1

•!.ires- si#+le pi#

PARTS LIST



VARIABLE

CAPACITOR

PICTURE OF COPONENTS



1K RESISTOR270K RESISTOR

RESISTORS

CONSTANTCAPACITOR



BATTERY

SWITCH



his !"#$%& transistor iscalled "P" switchingtransistor'> ?e"tures@

(ow current )ma* !%%ma*+ (ow voltage)ma* &%v+

>ppli%"tio#s@ ),+ -igh speedswitching' )!+ .ell suitable for

/ and -ome appliance

INFORMATION ABOUT

TRANSISTOR



• he basic way the beat fre0uencyoscillator )BFO+ works2 when a detectorcoil is above some metal2 it will change thefre0uency in the detector oscillator2 which

has the detector coil in the fre0uencydependent circuit' his relative simplemetal detector is not a real BFO2 but it isthe closest group of detectors' .hen the

metal is near the detector coil the signal issend to a timer pin' Internally thecalculation is made2 and showed on the(3D and some di4erent sounds are made'

“BFO” DETCTOR DESIGN



Advantages5

• ),+ Circuit diagram is very simple'

• )!+ .e can easily measure the

oscillation fre0uency of this circuit'

• )#+ It has some sensitivity through

which it can sense the metal easily'

Disadvantages5

• ),+ It has less sensitivity'

• )#+ Instead of variable capacitor we

cannot use any other capacitor for

ADVANTAGES AND

DISADVANTAGES



irport "#d Buildi#+ Se%urit

6etal detectors are used for airportand building security to determine

whether guns2 knives2 or otherweapons are being transported ontoaircraft or into public buildings'

APPLICATION



i&il /#+i#eeri#+

n Civil 3ngineering2 metal detector are usedto locate rebar )strengthen steel used as rodin concrete+ '7ebar detectors are less

sophisticated' Detectors can only locatemetallic ob8ects below the surface'



"#d $i#e Dete%tio#

• (and mine detector can sense as littleas %'9 grams of metal' 1o2 now5a5daysmilitaries are using land mine detector

to identify the land mine' 6ilitary hasused metal detector to pinpoint buriedland mines since world war,'



o#stru%tio# #dustr

• 6etal detectors are also used in theconstruction industry to locate steelreinforcement bars embedded in concrete2and to pinpoint metal pipes and wires in

:oors and walls' his is useful in avoidingunnecessary damage when replacingplumbing or wiring in a building or house'



• his pro8ect has been developedconsidering the need for low cost'

• he e0uipment is compact2 simple indesign and can be used practicallyanywhere needs'

• his circuit may also be constructedby using chip and the chip is C1!%$A'

conclusion



• 3ven the detectors with good coilcompensation could not always detect

the smaller target to the re0uired depthin all lanes'

• he metal detector gives a respectablerange for beat fre0uency operation)BFO+ up to $%mm '

• In our circuit oscillator will produce ashift in fre0uency' he end result is a

detector that operates like two5



•.3B 1O;7C35 )Access Date< %$=%&=!%,!+

• 7eferences<

• ),+ http<==www'principle'htm

•

)!+http<==www'freesimpleelectroniccircuitdiagra m'htm

•)#+

http<==www'simplemetaldetectorcircuitdiagram'htm

• )&+ www'wikipedia'com

BIBLIOGRAPHY

http://www.principle.htm/

http://www.freesimpleelectroniccircuitdiagram.htm/


http://www.simplemetaldetectorcircuitdiagram.htm/


http://www.wikipedia.com/

http://www.wikipedia.com/





http://www.principle.htm/



• .e would like to thank specially to6r' Aritra Achariya sir for helping usto choose this pro8ect'

• 6r' >ayanta ?hosh sir who are theassistant professors of 3C3

department of 1ir >'C Bose school of3ngineering ' -e helped us incompletion of the entire pro8ect '

ACKNOLEDGEMENT



• .e also thankful to 1" mam who

helped us by giving the format of thepro8ect'

•

.e acknowledge with gratitude toour teachers for theirencouragement and constructivesuggestions during the preparationof this pro8ect' 1uggestions toimprove the 0uality of this pro8ect is always welcome'



-A"@ O;



A";7I31

Metal Detector

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